UPGRADING OF INDONESIAN LOW RANK COAL BY STEAM DRYING METHOD

Datin Fatia Umar (R & D Centre for Coal and Mineral Technology)
Bukin Daulay (R & D Centre for Coal and Mineral Technology)
Hiromoto Usui (Department of Chemical Science and Engineering)
Slamet Suprapto (R & D Centre for Coal and Mineral Technology)

Indonesian Mining Journal
Vol 8, No 01 (2005): INDONESIAN MINING JOURNAL Vol. 8 No. 1 February 2005

Experiments were carried out to produce upgraded coals with low moisture content by steam drying method. An Indonesian low rank coal, Berau coal with moisture content of 16.13% and calorific value of 5324 cal/g in air dried basis (adb) was treated by steam drying at temperature of 225 - 300°C in an autoclave to study process temperature effect. The results of proximate and ultimate analyses show that moisture content decrease by increasing the temperature process. The moisture content reduces to 0.86% and the calorific value increases up to 6760 cal/g in adb when the coal has been treated at the temperature of 300°C. Furthermore, the specific surface area and combustion characteristics of coals were influenced by the upgrading process.